One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for South San Francisco you will be able to estimate when you can plant flower-of-an-hour.

Planting Calendar for Flower-of-an-Hour

Frost tolerance for flower-of-an-hour:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since flower-of-an-hour do ok in moderate cold you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant flower-of-an-hour in South San Francisco is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant flower-of-an-hour and expect a good harvest is probably September. You probably don't want to wait any later than that or else your flower-of-an-hour may not have a chance to really do well. If you are starting your flower-of-an-hour indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In South San Francisco the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Always keep in mind that USDA zone info for South San Francisco may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in South San Francisco you get surprised by a frost after January 31 be ready to cover your flower-of-an-hour in the event of a late frost.

USDA Zone Info for South San Francisco

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in South San Francisco

You may be interested in your other planting guides for South San Francisco.